It's hideous! How were the two of them not sacked immediately, or at least suspended while investigation takes place? (Although not much investigation would be needed since the entire incident was filmed.)
And the excuse in the article that "maybe the strap around the boy's neck was a bit too tight" despite being a load of rubbish when you see the video of what happened, you surely never ever restrain a person by the neck!?! Apart from necks being fragile and breathing easily obstructed, if you needed to restrain a person for your/their safety, it would surely be their limbs you would be in most danger from so no need to restrict neck & head movement at all?
But this incident wasn't restraint for safety purposes, it was an assault! By an adult man on a child, and a more vulnerable child at that.